Surgical retractor and liner

ABSTRACT

A surgical retractor liner and integral drape suitable for inserting in an incision and adjusting in place to prevent cross-contamination during surgery between the incised cavity and the surrounding skin of the patient. In one embodiment, a flexible elastic liner impervious to microorganisms has resilient inner and outer rings at opposite ends for holding the liner firmly in the incision. The outer ring is rolled down over itself drawing the liner taut and contiguous in the incision. In another embodiment, a skirt is sealingly joined at the outer ring and tapers outwardly and sealingly joins to a drape around a central aperture therein. The inner ring is inserted and expanded against the inner edge of the incision, and the outer ring is rolled down over the liner and skirt to draw the liner taut in the incision and to retract the sides of the incision while positively anchoring the drape in place around the area of the incision. In another embodiment, a lengthwise incrementally and automatically adjustable wound protector and retractor is provided.

FIELD OF THE INVENTION

[0001] The present invention relates generally to improvements insurgical devices, and more particularly to an improved adjustableretractor, and a retractor with a liner and integral drape therefor forpreventing contamination of incised cavity walls of various thicknessesduring surgery.

BACKGROUND OF THE INVENTION

[0002] The sides of an open incision, as well as matter such as bodyparts and fluids passing through the incision during surgery, areinherently susceptible to cross-contamination by infectiousmicroorganisms or like matter. Therefore, extreme care is required toinsure that any exposed fluids or tissues are completely isolated fromeach other.

[0003] Various designs have been proposed and utilized to preventtransmission of indigenous and exogenous contaminants to healthy viscerafrom infectious tissues or fluids. U.S. Pat. No. 5,524,644 by Berwyn M.Crook, filed Jun. 9, 1995, describes an incision liner and retractordevice which can be installed in an incision, incrementally adjusted inplace to form-fit a wide range of cavity wall thicknesses, and retractthe sides of the incision apart for better access to the abdominalcavity. It employs a flexible impermeable liner of pliable plasticmaterial with opposite ends terminating at inner and outer resilientO-rings. The inner O-ring is inserted in the cavity by squeezing itthrough the incision and allowing it to expand around the inner edge ofthe incision. The outer O-ring is then rolled down over the portion ofthe liner extending out of the incision until it is tight against theouter rim of the incision and the remaining portion is drawn taut andcontiguous with the incision sides. The outer O-ring is generally oblongin cross-section to provide a positive gripping surface for the fingersto roll the outer O-ring more easily, especially when the liner or thesurgeon's gloves are slippery.

[0004] In many instances, a surgical drape may be first placed over thepatient's body before the incision liner and retractor device isinstalled. This combination further reduces the risk ofcross-contamination between the open cavity and the skin around theincision, especially if an organ is brought outside the abdominal cavityto perform surgery on it. However, since the liner and drape are notintegrally connected, there is no assurance that the drape may not slidefrom beneath the outer O-ring and leave the patient's skin exposed in amost vulnerable region immediately adjacent to the incision.

[0005] Some prior art surgical protectors address this problem to alimited degree. For instance, U.S. Pat. No. 3,397,692 to Creager, Jr. etal. discloses an incised surgical device in which a resilient ringcemented around the rim of a central aperture in a drape is squeezedtogether and expanded in the cavity to grip the incised edge of theperitoneum. The drape is bunched together where it passes through theincision and then spreads out over the body surface in radiallydiminishing wrinkles. U.S. Pat. No. 4,188,945 to Wenander similarlyprovides a surgical cloth with a semi-rigid thread hemmed in around acentral aperture. A portion of the cloth around the aperture is gatheredtogether and inserted in an incision, and then enlarged under theincision edge by increasing the length of thread around the aperture.Like the surgical device of Creager, Jr. et al., a wrinkled surface iscreated in the incision and around the operating site. Consequently,neither device provides a relatively smooth surface in the incision andaround the wound where extracted viscera may be placed nor positiveretraction of the sides of the incision. In addition, there is no meansfor preventing external portions of the drape from slipping in and outof the incision with movement of the surgeon's hand.

OBJECTS OF THE INVENTION

[0006] Accordingly, it is an object of the present invention to providean improved surgical retractor liner and integral drape which preventexposure to cross-contamination by infectious fluids and solids betweenan incised cavity and the skin around the incision.

[0007] Another object of the invention is to provide a surgicalretractor liner and integral drape assembly which interfaces smoothlyand contiguously with the sides of an incision and with the skin aroundthe incision.

[0008] Still another object of the invention is to provide a retractorliner with integral drape which can be easily installed and adjusted inplace to fit a wide range of cavity wall thicknesses.

[0009] A further object is to provide a retractor liner which willpositively insulate an incision from exposure to indigenous andexogenous contaminants and positively retract the sides of the incisionfor a wider opening to the cavity.

[0010] A further object of the present invention to provide a relativelylow cost surgical retractor liner of simplified design which can beeasily installed in a wound and adjusted in place to form fit a widerange of cavity wall thicknesses for protection against harmfulcontaminants.

SUMMARY OF THE INVENTION

[0011] These and other objects and aspects of the invention areaccomplished in one embodiment by a surgical retractor liner andintegral drape which can be inserted in an incision and incrementallyadjusted tightly in place in the cavity wall and on the surrounding skinto prevent cross-contamination with body fluids and solids duringsurgery. It includes a flexible plastic film retractor liner imperviousto microorganisms with opposite ends terminating at inner and outerresilient O-rings. The inner O-ring is installed in the incision bysqueezing opposite sides together, inserting it through the incision andallowing it to expand around the inner edge of the incision. The lengthof the retractor liner is selected to allow a portion to extend out ofthe incision for rolling down until it is tight against the outer edgeof the incision and retracts the sides of the incision for widening theopening. A flexible plastic film skirt fixed at one end around the outero-ring, and coaxial with the retractor liner, tapers outwardly towardthe inner O-ring with the other end sealingly joining the rim of acentrally located aperture in a flexible drape. The extended length ofthe skirt is at least as long as the portion of the retractor linerfully extending out of the incision when the inner O-ring is expandedagainst the inner edge. This assures that the drape completely adheresto the surface around the incision and remains fixed in place by theretractor liner and by adhesive patches fixed to the drape. The size ofthe drape is sufficient to cover the area around the operating site andto prevent it from exposure to any contaminating fluids and tissue.

[0012] In another embodiment, the retractor liner comprises a flexibleliner of thin substantially elastic material, separate from the drape,secured at opposite open ends around resilient inner and outer O-rings.

[0013] In both embodiments, the outer O-ring in cross-section isgenerally circular with opposed flat sides in planes generallytransverse to the extended length of the liner for restoring the outerO-ring to its preformed configuration when turned about thecircumferential axis of rotation of the ring. The flat sides alsoprovide gripping surfaces for manually turning the outer O-ring withgreater ease, especially when the liner or the surgeon's gloves areslippery. The retractor liner may be constructed in a single linerlength with different circumferences for accommodating a wide range ofincision sizes and cavity wall thicknesses.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The foregoing and other objects, features, and advantages of theinvention will become more apparent from the following description ofthe preferred embodiments when taken in conjunction with theaccompanying drawings wherein:

[0015]FIG. 1 represents a perspective top view of one embodiment of asurgical retractor liner and integral drape device according to theinvention;

[0016]FIG. 2 is a side view partially in cross-section of a portion ofthe embodiment of FIG. 1;

[0017]FIG. 3 is an enlargement in cross section of an upper portion ofthe embodiment shown in FIGS. 1 and 2;

[0018]FIG. 4 is a view in radial cross section of an alternateembodiment of an O-ring for use in the upper portion of the assemblyshown in FIG. 3; and

[0019]FIGS. 5A and 5B are schematic illustrations of the device in twostages of installation in an incision;

[0020]FIG. 6 is an isometric view of another embodiment of a retractorliner according to the invention, in a fully extended state and withportions cut away;

[0021]FIG. 7 is a view in longitudinal cross-section of an outer end ofthe retractor liner of FIG. 6;

[0022]FIGS. 8A and 8B is a schematic representation in longitudinalcross-section of the retractor liner of FIG. 6 partially installed in asurgical wound; and

[0023]FIG. 8 schematically illustrates the retractor liner of FIG. 6 intwo stages of installation in an incision.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Referring now to the drawings wherein like reference charactersdesignate like or corresponding parts throughout the several views,there is shown in FIG. 1 a surgical retractor liner and integral drapedevice 10 comprising an incision retractor liner 12 of uniformcircumference along its length coaxially extending through a skirt 14and a central aperture 16 a in a drape 16.

[0025] As best seen in FIG. 2, retractor liner 12 and skirt 14 haveadjacent upper ends which wrap around an outer O-ring 18 and overlap atannular edges 12 a and 14 a (FIG. 3) and seal to each other and to theouter side skirt 14. A lower end portion of retractor liner 12 wrapsaround an inner O-ring 20 and overlaps at an annular edge 12 b and sealsto the outer side of retractor liner 12; whereas a lower end of skirt 14is sealed around the perimeter of aperture 16 a. Retractor liner 12 isessentially uniform in circumference along a central longitudinal axisdefined by the extended length of the liner. Skirt 14 is coaxial withretractor liner 12 and tapers outwardly to aperture 16 a.

[0026] Outer O-ring 8 is generally oblate in cross-section with opposedupper and lower flat chordal sides 18 a and lab substantially normal tothe extended length of retractor liner 12. Sides 18 a and 18 b arelocated equidistant from, and on opposite sides of, the centroid of theradial cross-section through O-ring 18. The oblate shape provides anover-center snap action when O-ring 18 is rolled about itself ontoretractor liner 12 and skirt 14 for incrementally shortening the upperends and for resisting unrolling after being shortened.

[0027] Inner O-ring 20 is entirely circular in cross-section, but mayhave a similar cross-section as O-ring 18 for incrementally shorteningthe lower end of retractor liner 12.

[0028]FIG. 4 illustrates in radial cross-section an alternate embodimentof an outer O-ring 18. The upper and lower sides 18 a and 18 b taperoutwardly from opposite sides of a plane normal to the extended lengthof liner 12 thereby allowing O-ring 18 to be turned with less resistancearound its annular axis due to the lesser mass near the innercircumference O-ring 18. This structure is particularly desirable forlarge diameter rings having relatively large diameter cross-sections.

[0029] The materials for making assembly 10 are selected to insurestability when installed. One preferred material for retractor liner 12,skirt 14 and drape 16 is a substantially inelastic heat-sealable 3-milpolyolefin plastic film, such as Saranex™ film 2050 by The Dow ChemicalCompany. Another preferred material for liner 12 and skirt 14 is asubstantially elastic heat-sealable 2-mil polyurethane film, such asDureflex® PT6100S by Deerfield Urethane, Inc.

[0030] The polyurethane material has been found to provide certainadvantages not available with the Saranex™ polyolefin material. Forinstance, the elastic polyurethane material takes up any lengthwiseadjustment which cannot be fully accommodated by the incrementaladjustments made by rolling the O-ring 18. In addition, the elasticpolyurethane provides a better retraction function along the edges ofthe incised wound. This is believed due, at least in part, to the betterwound edge margin gripping action resulting from the axial take-up ofthe elastic polyurethane.

[0031] The difference between the non-elastic polyolefin material andthe elastic polyurethane may be seen from a test wherein five 1″×3″specimens of each of these materials were stretch tested at roomtemperature (+75° F.) and permanent deformation (deflection) calculatedfrom its load vs. displacement curve. The average deflection of thepolyolefin film was approximately 0.354 inch/inch, while thepolyurethane specimen deflection averaged approximately 0.167 inch/inch.

[0032] O-rings 18 and 20 are preferably preformed of an elastomericmedical-grade polyurethane of sufficient hardness to retain the ringsexpanded in place around the inner and outer rims of the incision. TheO-ring material must be compliant enough to allow the fingers to turnthe outer O-ring 18 over 180° around its annular axis from the preformedconfiguration. They may be color-coded with different colors, such aswhite and blue, for easier recognition of the correct O-ring to beinserted in an incision.

[0033] Drape 16 may be adhered directly to the skin of the patient or toan underlying drape by an adhesive spread over the underside of thedrape, or by adhesive patches 22 at selected locations on the undersideof the drape. The size of drape 16 is selected to provide effectiveprotection from exposure to infectious fluids and tissue in the vicinityof the incision.

[0034] The length of a fully extended retractor liner 12 is typicallyaround 150 mm to accommodate most wall thicknesses at the incision. Anassortment of liner and O-ring diameters are provided to accommodatedifferent lengths of incisions, and the personal preference of thesurgeon. U.S. Pat. No. 5,524,644, supra, discloses a table of liner andO-ring diameters available for different incision lengths, and itsdisclosure is incorporated by reference herein. The urethane O-rings aretypically in the range of 50-90 Shore A durometers.

[0035] The diameter of an upper length of skirt 14, in a relaxed statebefore stretching around O-ring 18 and sealing it at edge 14 a,corresponds substantially to the diameter of retractor liner 12. Theremaining lower portion tapers outwardly to the diameter of aperture 16a which is slightly larger than the diameter of retractor liner 12 toallow clearance for retractor liner 12 to be stretched into contact withthe outer rim of the incision. The length of skirt 14 must not beshorter than retractor liner 12 by an amount greater than the thicknessof the wall at the incision. If the difference were greater, the drapewill not adhere completely to the skin immediately adjacent to theincision. Of course, if the difference is less than the wall thickness,the lower end of skirt 14 will merely bunch up around the uninsertedportion of retractor liner 12 and roll onto O-ring 18 but still providea satisfactory seal. Typically, the thickness of abdominal walls rangesbetween 25 mm and 75 mm. Therefore, for an overall liner length of 150mm, an effective skirt length should not be shorter by more than 25 mm,namely an overall length of 135 mm.

[0036] A typical installation of the retractor liner and integral drapeassembly 10 is illustrated in two stages in FIGS. 5A and 5B. In FIG. 5a,retractor liner 12 is inserted into an incision in the abdominal wall Awith the inner O-ring 20 expanded against the inner rim of the incisionand drape 16 adhered to the skin, or to an underlying drape not shown.In this installation skirt 14 is shorter than retractor liner 12 by adifference slightly less than the thickness of the abdomen wall, therebycausing skirt 14 to bunch up around fully extended retractor liner 12.In FIG. 5B, the upper end of the assembly containing O-ring 18 is rolleddown over the outside of skirt 14, abuts the top of drape 16 with skirt14 drawn taut against the incision, and retracts the sides of theincision to widen the opening. Drape 16 is thusly positively anchoredagainst slipping out from under the rolled down portions of liner 12 andskirt 14.

[0037] Referring now to FIG. 6, an adjustable retractor device 110includes a thin relatively elastic liner 112, uniform circumferencealong its length and impervious to solids and fluids containing bacteriaand other harmful contaminants.

[0038] As best seen in FIG. 7, the upper end portion 112 a of the liner112 wraps around outer O-ring 118 and terminates in an annular edgeportion 112 c sealed around the outer side of liner 112. At least oneO-ring, such as the O-ring 118, is generally oblate in cross-sectionhaving opposed flat chordal side surfaces 118 a and 118 b which aretransverse, i.e. substantially normal, to the liner central longitudinalaxis defined by the extended length of liner 112, as shown in FIGS. 6-8b. As shown, the chordal surfaces 118 a and 118 b are locatedequidistant from, and on opposite sides of, the centroid of thecross-section. The surfaces 118 a and 118 b provide surface means forpurposes to be described.

[0039] Inner O-ring 120 is secured to lower end portion 112 b in thesame manner as O-ring 118, except the configuration in cross section isentirely circular. If desired, both O-rings may have the samecross-sectional shape as O-ring 118 to provide reversibility to theretractor liner device 110.

[0040] The oblate shape of the O-ring 118 provides stability in a planeperpendicular to the longitudinal axis of the liner 112 and provides anover center snap action when rolled about itself and the liner, therebyproviding incremental shortening in predetermined increments andresistance to lengthening after shortening.

[0041] The materials and dimensions of adjustable surgical device 10 areselected to ensure stability when installed. A preferred elasticmaterial suitable for liner 112 is a 2-mil polyurethane film, such asDureflex® PT61005 supra. It is produced in seamless tubular form or by aflat sheet in a cylindrical form with the meeting margins along the sideoverlapped and sealed. A nominal liner length suitable for minimallyinvasive surgery is typically around 150 mm. Liner diameters will varyaccording to wound length as will be discussed.

[0042] Outer and inner O-rings 118 and 120 are preferably preformed ofan elastomeric medical grade material of sufficient hardness to retainO-rings 118 and 120 expanded in place around the inner and outer edgesof the wound. Like O-ring 18, the material must be compliant enough toallow O-ring 118 to be turned by the fingers over 180 degrees around itsannular axis from the preformed configuration. Urethane is therefore thepreferred elastomeric material. When the O-rings are of differentconfigurations, the O-rings are preferably color-coded with differentcolors, such as white and blue, for aiding in recognizing the correctend of the protector to be inserted in the wound.

[0043] The inside circumferences of O-rings 118 and 120 generallycorrespond to the outside circumference of liner 112. By way of example,a urethane O-ring 118 for use with a liner 110 mm (4.33 inches) indiameter has a diameter across the transverse cross section of about7.94 mm ({fraction (5/16)} inch) with a distance between parallel flatsides 118 a and 118 b of approximately 6.10 mm (0.240 inch). O-ring 120has a diameter of its circular cross-section of about 7.94 mm ({fraction(5/16)} inch). of course, the sizes of the O-rings and liners will varyaccording to wound size and wound wall thickness, and the personalpreference of the surgeon will affect the choice of size for aparticular surgical procedure.

[0044] The following table sets forth a preferred relation betweenincision length and liner and O-ring and liner diameters. It also setsforth the preferred cross-sectional diameters for each O-ring, it beingunderstood that O-ring 18 has opposed flats and is, therefore, oblateand not circular in cross-section. O-Ring Incision Liner Diameter CrossSectional Length (mm) (mm) Diameter (mm) 10 30 5.15 20 30 5.15 30 607.13 40 60 7.13 50 80 7.52 60 80 7.52 70 110 7.92 80 110 7.92 90 1107.94 100 130 9.53 110 130 9.53 120 150 11.11 130 150 11.11 140 170 12.70150 170 12.70 160 190 14.29 170 190 14.29 180 210 15.88 190 210 15.88200 230 15.88

[0045] The durometers of the O-rings set forth in the above table shouldbe in a range of 50 to 90 Shore A. The preferred material is urethane,but silicone could be used with some loss of stability afterinstallation and adjustment. The best stability is achieved by using amaterial having a high modulus of elasticity with a ring, asmanufactured; having a minimum of residual stresses and strains. Thesize of the flats affects both gripability for adjustment and stabilityafter adjustment, since the larger the size of flats for a given O-ringcross-sectional diameter, the less stability that exists. By way ofexample, a preferred flat width for an O-ring having a cross-sectionaldiameter of 7.94 mm ({fraction (5/16)} inch) is 6.10 mm (0.240 inches).It is expected that with increasing diameters each flat width shouldincrease proportionately based on a formula: W=xD where W is the widthof the flat; D is the diametrical cross-section of the O-ring; and x isa constant equal to 0.85 for a urethane ring having a hardness withinthe ranges stated.

[0046] In using the adjustable surgical device in a minimally invasiveabdominal surgical procedure, the abdomen is routinely prepared withantiseptics and dried; the site for the incision is traced on theabdomen and covered with a surgical drape; and a muscle-split is made atthe site through the peritoneum. As illustrated in FIGS. 8A and 8B,retractor and liner 110 is placed in wound W₁ by squeezing inner O-ring120 into a tight oblong shape and inserting it lengthwise through theincision and letting it expand inside the peritoneum around the inneredge of the wound. Outer end portion 112 a is gripped by the thumb andfingers at flat sides 118 a and 118 b of outer ring 18 (FIG. 7) andturned outwardly, in opposite directions shown by arrows A, rollingliner 112 on the O-ring until it abuts the outer edge of the wound W₁ asshown in FIG. 8B. However, as a result of the elasticity of the linermaterial, any lengthwise adjustment not accommodated by the incremental.adjustments causes the part of liner 112 in the wound between O-rings118 and 120 to be thereby drawn into contiguous contact with the edgemargins of wound W₁ and hence with the wound walls to provide aself-retaining protective barrier during surgery which is impervious tocontaminating solids and fluids. If desired, the protector 10 can alsobe pre-adjusted prior to insertion, or partially pre-adjusted.

[0047] Some of the many advantages and novel features of the inventionshould now be readilapparent. For example, the invention provides animproved liner and drape device which prevents exposure between anincised cavity and the skin around the incision to cross-contaminationby infectious fluids and tissue. The assembly is positively anchored inplace around the operating site by the installed liner, smoothlyinterfaces against the sides of the incision and the surrounding skin,and retracts the sides of the incision for a wider opening. It can beeasily installed in an incision and adjusted in place to fit a widerange of cavity wall thicknesses as well as provide positive insulationof an incision and surrounding skin from indigenous and exogenouscontaminants.

[0048] A relatively simple and inexpensive surgical retractor liner isprovided for protecting wounds from exposure to contamination. It can bequickly and easily installed in a wound and adjusted in place toform-fit a wide range of cavity wall thicknesses, and it stays in placeafter insertion. A fewer number of combinations of sizes of protectorsare needed to accommodate a variety of incision sizes and cavity wallthicknesses.

[0049] Of course, it will be understood that various changes in thedetails, materials, steps and arrangement of parts, which have beenherein described and illustrated in order to explain the nature of theinvention, may be made by those skilled in the art within the principleand scope of the invention as expressed in the appended claims.

1. A surgical device (10) for preventing cross-contamination duringsurgery of infectious fluids and solids between an incision and theexternal surface around the incision, comprising in combination: atubular liner (12) of flexible material open at opposed ends thereof; afirst resilient ring (20) secured around one of said liner ends (12 b)deformable into an oblong shape for insertion with a portion of saidliner (12) into the incision and expansion against the inner edge of theincision; a second resilient ring (18) secured around said one liner end(12 a) for rolling up adjacent portions of said liner (12) on itself andagainst the outer edge of the incision; a continuous skirt (14) offlexible material having opposed first and second ends, said first end(14 a) sealingly secured around said one liner end (12 a) and coaxialwith said liner (12) in their fully extended positions, said skirt (14)adapted to roll up with adjacent positions of said liner (12); and adrape (16) of flexible material having a central aperture (16 a)sealingly secured around said second skirt end, the length of said skirt(14) being sufficient for said drape (16) to adhere to the externalsurface immediately adjacent to the incision.
 2. A device (10) accordingto claim 1 wherein said skirt (14) is shorter than said liner (12) inthe extended positions.
 3. A device (10) according to claim 1 whereinsaid length of said liner (12) exceeds the length of said skirt (14) byless than about 25 mm.
 4. A device (10) according to claim 1 wherein thelength of said liner (12) exceeds the length of said skirt (14) by anamount in the range of about 25 mm and 75 mm.
 5. A device (10) accordingto claim 1 wherein said liner (12) is of uniform circumference along theextended length, and said skirt (14) tapers outwardly along the extendedlength from said first skirt end (14 a).
 6. A device (10) according toclaim 1 wherein said liner (12) and said skirt (14) are made of a sheetof a substantially inelastic plastic of about 3-mil polyolefin.
 7. Adevice according to claim 6 wherein said sheet of plastic has adeformation of approximately 0.354 inch/inch.
 8. A device (10) accordingto claim 1 wherein said liner (12) and said skirt (14) are made ofsubstantially elastic material.
 9. A device according to claim 8 whereinsaid elastic material has a deformation of approximately 0.167inch/inch.
 10. A device (10) according to claim 1 wherein said drape(16) is made of a backing about 3-mil plastic sheet.
 11. A device (10)according to claim 1 further comprising: adhesive patches (22) disposedon one side of said drape (16) for adhering to a patient's skin or anunderlying surgical drape.
 12. A device (10) according to claim 1wherein said second resilient ring (18) has substantially flat surfaces(18 a, 18 b) on opposite sides for enabling tactile gripping and rollingadjacent portions of said liner (12) and said skirt (14) onto saidsecond resilient ring (18) in predetermined increments to shorten saidliner (12) and to resist subsequent lengthening thereof.
 13. A device(10) according to claim 12 wherein said second resilient ring surfaces(18 a, 18 b) are transverse to the extended length of said liner (12)and equidistant from the centroid of a radial cross-section thereof. 14.A device (10) according to claim 12 wherein said second resilient ringsurfaces (18 a, 18 b) taper outwardly from a plane transverse to theextended length of said liner (12).
 15. A surgical retractor device (10)comprising: a tubular liner (12) open at each of opposed ends thereof,said liner (12) being made of a pliable material impervious to solid andfluid contaminants for inserting lengthwise in a wound; a continuousskirt (14) of flexible material having opposed first and second ends,said first end (14 a) sealingly secured around one of said liner ends(12 a) and coaxial with said liner (12) in their fully extendedpositions; an inner O-ring (20) secured around the other one of saidliner ends (12 b), said inner O-ring (20) having a preformed resilientconfiguration for overlapping the inner edge of the wound and forsqueezing into an oblong shape insertable with a lengthwise portion ofthe liner (12) adjacent to said inner O-ring (20) in the wound; and anouter O-ring (18) secured around said one liner end (12 a) and saidfirst skirt end (14 a), said outer O-ring (18) having surface meansformed integral therewith for overlapping the outer edge of the woundand for rolling adjacent portions of said skirt (14) and said liner (12)lengthwise on themselves about the outer O-ring (18) to shorten theliner (12) in predetermined increments; said inner (20) and outer (18)rings cooperating with said flexible liner (12) when installed in anincision both to protect the edges of the incision from contaminationand to retract the edges from one another to facilitate surgery throughthe incision, whereby the liner (12) length can be adjusted before orafter placement in the wound.
 16. A device (10) according to claim 15wherein said skirt (14) is shorter than said liner (12) in the extendedpositions.
 17. A device (10) according to claim 15 wherein said lengthof said liner (12) does not exceed the length of said skirt (14) by morethan about 25 mm.
 18. A device (10) according to claim 15 wherein thelength of said liner (12) exceeds the length of said skirt (14) by anamount in the range of about 25 mm and 75 mm.
 19. A device (10)according to claim 15 wherein: said surface means on said outer O-ring(18) includes opposed flat surfaces (18 a, 18 b) enabling tactilegripping and rolling of said skirt (14) and said liner (12) onto saidouter O-ring (18).
 20. A device (10) according to claim 19 wherein: saidopposed surfaces (18 a, 18 b) lie in parallel planes perpendicular to alengthwise extension of said liner (12) to provide said outer O-ring(12) with an oblate cross-section.
 21. A device (10) according to claim19 wherein said second ring surfaces (18 a′, 18 b′) taper outwardly froma plane transverse to the extended length of said liner (12).
 22. Aliner and drape device (10) incrementally adjustable lengthwise for usein surgery comprising: an elongate flexible liner (12) open at oppositeends; a flexible skirt (12) open at opposite ends, an inner ring (20)secured to one of said liner ends (12 b); an outer ring (18) securedaround one of said skirt ends (14 a) and around the other one of saidliner ends (12 a), said outer ring (18) having an oblate transversecross-section defined by a diametrically opposed pair of arcuatesurfaces interconnected by an opposed pair of chordal surfaces (18 a, 18b); a flexible drape (16) having a central aperture (16 a) securedaround the other one of said skirt ends, the extended length of saidskirt (14) being sufficient for said drape (16) to adhere the skin nextto the incision; and said inner (20) and outer (18) rings cooperatingwith said flexible liner (12) when installed in an incision both toprotect the edges of the incision from contamination and to retract theedges from one another to facilitate surgery through the incision. 23.An incrementally and automatically adjustable surgical device (110)comprising: an elongate liner (112) of substantially elastic materialopen at opposed ends; a first resilient ring (120) secured around one ofsaid ends (112 b) deformable into an oblong shape for insertion with aportion of said liner (112) into a wound and formed to expand againstthe inner edge of the wound; and a second resilient ring (118) securedaround the other of said liner ends (112 a) and formed with an oblatecross-section having opposed chordal surfaces (118 a, 118 b) forenabling the gripping and rolling of a remaining portion of said liner(112) in increments on itself and against the outer edge of the wound,whereby the liner length may be adjusted in increments before placementin the wound and automatically adjustable lengthwise after placement.24. An adjustable surgical device (110) according to claim 23 whereinsaid elastic material has a deformation of approximately 0.167inch/inch.
 25. An adjustable surgical device (110) according to claim 23wherein: said chordal surfaces (118 a, 118 b) are disposed transverse tothe length of said liner (112) in both an as-manufactured condition andan incrementally-adjusted condition.
 26. An adjustable surgical device(110) according to claim 25 wherein: said chordal surfaces (118 a, 118b) are flat and are located in parallel planes equidistant from thecentroid of said cross-section.
 27. An adjustable surgical device (110)according to claim 26 wherein: said parallel planes are perpendicular tothe central longitudinal axis of the liner (112).
 28. An adjustablesurgical device (110) according to claim 26 wherein: said liner (112) isa thin sheet of generally cylindrical form wrapped about said rings(118, 120) and secured thereto.
 29. An adjustable surgical device (110)according to claim 23 wherein: each of said rings (118, 120) is ofurethane having a hardness in a range of about 50 to about 90 Shore Ascale.
 30. A lengthwise adjustable surgical device (110) for use insurgery comprising: a elongate elastic liner (112) open at oppositeends, an inner ring (120) secured to said liner (112) at one end (112b), an outer ring (118) secured to said liner (112) at the opposite end(112 a), said outer ring (118) having an oblate transverse cross-sectiondefined by a diametrically opposed pair of arcuate surfacesinterconnected by an opposed pair of chordal surfaces (118 a, 118 b),said chordal surfaces (118 a, 118 b) extending outwardly from said liner(112) in a plane perpendicular to a central axis extending lengthwise ofsaid liner (112), said outer ring (118) being in a minimally strainedstable condition when said chordal surfaces (118 a, 118 b) are lying insaid plane, said outer ring (118) being operable, when rolled 180° aboutits centroid, to roll said liner (112) about itself and thereby toadjust the length of the liner (112) in increments.
 31. A lengthwiseadjustable surgical device (110) according to claim 30 wherein at leastsaid outer ring (118) is of urethane having a durometer in a range ofabout 50 to about 90 Shore A.
 32. A lengthwise adjustable surgicaldevice (110) according to claim 30 wherein the chordal width of eachchordal surface (118 a, 118 b) is defined substantially by the formula:W=xD, wherein W is the width, x is a constant of 0.85, and D is thediametrical distance between said arcuate surfaces.